$OpenBSD: patch-lib_runcmd_c,v 1.1 2015/02/05 22:58:24 sthen Exp $
--- lib/runcmd.c.orig	Thu Feb  5 13:03:13 2015
+++ lib/runcmd.c	Thu Feb  5 13:04:05 2015
@@ -36,7 +36,7 @@
 #endif
 
 /* Determine whether we have setenv()/unsetenv() (see setenv(3) on Linux) */
-#if _BSD_SOURCE || _POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600
+#if _BSD_SOURCE || _POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600 || __OpenBSD__
 # define HAVE_SETENV
 #endif
 
